ASU researchers identify potential target to improve sleep in children

September 19, 2018

Between 25 and 30 percent of children under the age of 18 in the United States do not getenough sleep. Sleep deprivation in children can lead to behavioral and mood problems that can negatively affect school performance, social interactions and physical well-being.

And children from lower-middle-class families or families who live at or near the poverty line get less sleep and lower quality sleep than their peers from families with more income and resources.Sleep deprivation in children can lead to behavioral and mood problems. Photo by Annie Spratt/UnsplashDownload Full Image

“Children from lower-middle-class and poor families get less sleep overall, and their quality of sleep isworse,” said Leah Doane, associate professor of psychology. “We wanted to test whether the socioeconomic status early in a child’s life affected their sleep when they were older and try to identify a mechanism for how socioeconomic status affected sleep.”

Identifying the pathways by which socioeconomic status affects sleep is important because socioeconomic status itself is difficult to change.

Sleep and socioeconomics seven years later

The study is part of ASU’s Arizona Twin Project, and all participating children were twins. The researchers studied 381 children, at 12 months and 8 years of age.

When the children were 12 months old, the researchers first used a phone survey to collect information about the demographics of the participating families, including income and number of family members, and also about the health and development of the children.

Seven years later, the families participated in an intensive,one-week assessment that examined the physical healthand academic achievement of the children. The researchers again collected information about the demographics of the family.

To determine the socioeconomic status and amount of resources available to each child, the researchers calculated an income-to-needs ratio, which divided the overall income by the number of family members. The researchers calculated the income-to-needs ratio twice for each child: at age 12 months and 8 years. A small ratio means there are less resources available to children and their family members. Based on the income-to-needs ratio, 47 percent of the 191 families in the study sample were classified as lower-middle-class or living at or below the poverty line.

During the weeklong assessment, the parents completeddaily questionnaires about the physical health of the children, and eachchild wore an activity-tracking bracelet for one week.The bracelet allowed the researchers to measure how long it took children to fall asleep and the quality of their sleep, or how long they slept without waking.

The researchers found a small income-to-needs ratio, or lower socioeconomic states, when a child was 12 months old predicted less sleep and poorer sleep quality at age 8. This relation was true even if the family’s income-to-needs ratio had increased during the seven years.

The importance of home

To understand the process of howsocioeconomics affectsa child’s sleep, the researchers studied the home environments of the 381 participating children.During the weeklong assessment, the researchers visited each home twice. To assess the home environment, theyused a questionnaire called the Middle Childhood HOME that measures how the home environment contributes to and supports a child’s physical, emotional and social development.

“The Middle Childhood HOME inventory is designed to assess a number of aspects of the home environment, including family routines, parent-child relationships, emotional climate in the home, what kinds of resources and learning materials are available to the children, extracurricular activities and physical details of the home,” said Reagan Breitenstein, a psychology graduate student who is second author on the study.

The researchers thought that aspects like whether there was a lot of noise,or if it was dark in the child’s bedroom or if the surroundings were chaotic would be important factors affecting sleep, but these factors were not among the most influential.

It was the combination of all aspects of the home environment — the physical environment, the level of autonomy given to the children and the quality of parenting — that determinedthe quality of the children’s sleep. When the researchers included the home environment in the analysis, the socioeconomic status of the family no longer predicted the quality of sleep.

“The totality of the home environment, how the home was structured when the children were 8 years old, was what affectedtheir sleep,” Doane said.

The combination of home environment and lower socioeconomic status seven years prior was associated with less time sleeping, longer times to fall asleep and more variable sleep schedules, like a different bedtime each night.

“Because the home environment was a pathway through which early socioeconomic status affected sleep in later childhood, it might be an ideal place to direct efforts to improve child sleep,” Breitenstein said.

Future work with the Arizona Twin Project

Thegoal of the Arizona Twin Project is to understand genetic and environmental influences on the development of children. The project is directed by ASU’s Kathryn Lemery-Chalfant, professor of psychology; Mary Davis, professor of psychology; and Doane.The current study is the beginning of a series of planned studies that examine environmental influences on sleep and other biological factors in children. The researchers next plan to study the impact of genetics on sleep quality in the twin participants and to identify possible home interventions that could improve the sleep of children.

The study was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Developmentand the William T. Grant Foundation.

Reagan Breitenstein, a psychology graduate student, is second author on the study.

Kimberlee D’Ardenne

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Twenty years ago, an ebullient, young assistant professor named Omar Yaghi sat down in Professor Michael O’Keeffe’s office in what was then the Arizona State University Department of Chemistry and Biochemistry. O'Keeffe asked him if he could synthesize a particularly beautiful, complex crystal in his lab. Yaghi brashly replied, “Of course!” And so began the field now known as reticular che...

ASU emeritus professor wins Aminoff Prize in crystallography

A passion for the visual beauty of reticular chemistry bears fruit with prestigious award

September 19, 2018

Twenty years ago, an ebullient, young assistant professor named Omar Yaghi sat down in Professor Michael O’Keeffe’s office in what was then the Arizona State University Department of Chemistry and Biochemistry. O'Keeffe asked him if he could synthesize a particularly beautiful, complex crystal in his lab. Yaghi brashly replied, “Of course!” And so began the field now known as reticular chemistry.

“It was a relationship born in heaven,” said Austen Angell, Regents’ Professor in the School of Molecular Sciences. Emeritus Regents' Professor Michael O’Keeffe from ASU’s School of Molecular Sciences will be awarded, along with University of California, Berkeley Professor Omar Yaghi, the prestigious Gregori Aminoff Prize in Crystallography in 2019.Download Full Image

Now, the Royal Swedish Academy of Sciences has announced that ASU Emeritus Regents' Professor O’Keeffe and Yaghi, of the University of California, Berkeley, have won the prestigious Gregori Aminoff Prize in Crystallography for 2019, “for their fundamental contributions to the development of reticular chemistry."

“This is a well-deserved achievement by one of our most famous scholars,” said Professor Neal Woodbury, director of the School of Molecular Sciences in the College of Liberal Arts and Sciences at ASU. “Professor O’Keeffe has performed decades of groundbreaking work on the fundamental structure and properties of molecules and materials. He has been a pioneer in the creation of materials made from linking molecular building blocks into porous frameworks, a field that has been used to develop everything from catalysts to materials for specific chemical separation processes.”

Metal-organic frameworks, universally called MOFs, are a relatively new class of crystalline materials with unprecedented porosities and capacities to absorb gases, with many practical applications.

MOFs and their properties were discovered in the late ‘90s at ASU by Yaghi and his group. Yaghi was joined by O’Keeffe in developing the theory and practice of synthesis of MOFs with designed structure and properties — reticular chemistry.

“What has been most remarkable to me in MOF chemistry over the years was the constant Greek chorus saying that ‘It can’t be done,'" O'Keeffe said. "But subsequent history has been an illustration of the truism 'never say never.' Naysayers can only be proved wrong.”

An early example of a MOF with a two-periodic net formed of strong bonds was what is now known as MOF-2 from the Yaghi group. In this compound, square "paddle wheels" containing two zinc atoms are linked in a periodic square array. Microporosity and high surface area was evidenced by the ability to adsorb gases at low pressures.

O’Keeffe explained: “Those who went to conferences where such materials were discussed two decades ago heard the chorus: 'They won’t be stable.' They were. 'The frameworks will collapse when solvent is removed." They didn’t. 'They won’t be porous.' They were — they adsorbed gases at low pressures and had "permanent" porosity."

O’Keeffe recalls his initial response when he and Yaghi were colleagues at ASU and the young professor showed him the structures of MOF-2 and MOF-3: "There are simply too many atomsThis was a play on the words, "My dear young man ... your work is ingenious ... there are simply too many notes,’’ uttered by the emperor to Mozart in Peter Shaffer’s play "Amadeus."."

O’Keeffe came from the austere world of metal-oxide chemistry and found structures with benzene rings and carbon-hydrogen bonds far too baroque for his taste. No doubt with tongue in cheek, Yaghi thanked him in the MOF-2 paper for his "interest."

The now-iconic MOF-5 structure. It has unprecedented surface area, porosity and stability. It opened a whole new field of chemistry and was an initiation point for a productive collaboration between Omar Yaghi and Michael O'Keeffe on the topology of MOFs.

Professor Michael O'Keeffe

The yellow ball in the center of the MOF-5 structure indicates the empty space which can be used to store gases.

Professor Michael O'Keeffe

Metal-organic frameworks, universally called MOFs, are a relatively new class of crystalline materials with unprecedented porosities and capacities to absorb gases, with many practical applications.

Professor Michael O'Keeffe

But the now-iconic MOF-5, which came shortly thereafter and earned O’Keeffe, Yaghi and coworkers a publication in Nature, changed everything. This had truly unprecedented surface area, porosity, and stability. The zinc carboxylate cluster with the six carboxylate carbons forming a regular octahedron but with tetrahedral symmetry was elegantly beautiful especially when linked in such regular arrays — by, yes, those benzene rings — like terra-cotta warriors, and O’Keeffe jumped aboard the bandwagon.

MOFs also have exceptional promise as materials to remove carbon dioxide from the emissions of power stations burning fossil fuels. They are therefore important components of the switch to cleaner energy production.

MOFs have many other applications in chemical industry, such as separations of chemicals and catalysis to speed up specific chemical processes. The subject is one of the fastest-growing areas of materials chemistry: Thousands of new compounds are reported every year.

The prize ceremony will be held at the annual meeting of the Royal Swedish Academy of Sciences on March 31, 2019. A symposium on the theme of the prize will be organized in association with its awarding.